Lighting fixture



June 19, 1962 CHAN 3,040,172

LIGHTING FIXTURE Filed Nov 12, 1958 2 Sheets-Sheet 1 M W M June 19, 1962CHAN 3,040,172

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ATTORNEYS United States Patent Ofiice 3,040,172 Patented June 19, 19623,040,172 LIGHTING FIXTURE Kingsley Chan, New York, N.Y., assignor toLightoher, Incorporated, a corporation of New York Filed Nov. 12, 1958,Ser. No. 773,225 1 Claim. (Cl. 24078) The invention relates to the artof spot projection type of lighting fixtures and more particularly tothe baffle therefor.

It is among the objects of the invention to provide a bafile for a spotprojection type of lighting fixture, that may readily be fabricated atrelatively low cost from inexpensive materials, that may readily bemounted into the fixture and which will substantially eliminatereflections due to non-axial components of light from the electric lampof the fixture, thereby substantially eliminating undesirable brightnesswithin the confines of the bafile which would provide a bright region onthe ceiling that contrasted strongly with the surrounding area and hencewhich would focus the attention of the viewer on the source of the lightitself rather than on the object being illuminated.

According to the invention these objects are accomplished by thearrangement and combination of elements hereinafter described andparticularly recited in the claim.

In the accompanying drawings in which are shown one or more of variouspossible embodiments of the several features of the invention,

FIG. 1 is a longitudinal sectional view of a lighting fixtureincorporating the invention,

FIG. 2 is a top plan view of the baflie unit, and

FIG. 3 is a detail sectional view taken along line 3-3 of FIG. 2.

Referring now to the drawings, the lighting fixture comprises asubstantially cylindrical casing 11, the top wall 12 of which has ahollow receptacle 13 rising therefrom. A mounting plate 14 is secured asby screws 15 over the mouth of the receptacle and carries a lamp socket16 in which a conventional lamp such as a PAR 38 projector lamp 17 ismounted.

The casing 11 is illustratively mounted in a recess in a ceiling 21 sothat its lower end 22 is substantially flush with the surface 21 of theceiling. Although the casing 11 may be mounted in any suitable manner,in the embodiment shown, an annular mounting member 23 is providedcomprising a plate having a circular opening 25 and having a cylindricalportion 26 of diameter substantially equal to that of the opening 27 inthe ceiling 21 providin access to the recess. The cylindrical portion 26is formed integral with plate 23 between its inner and outer edges andencompasses the lower portion of the cylindrical casing 11, the portionsof the plate 23 inwardly and outwardly of cylindrical portion 26defining flanges 28, 29.

Seated on flange 28 is an annular gasket 32 positioned beneath the lowerend 22 of casing 11, a plurality of screws 33 securing the casing 11 tothe cylindrical portion 26.

Positioned in the casing 11 and extending axially thereof from its lowerend is a baffle unit 36 which comprises a cylindrical sleeve, preferablyof molded heat resistant plastic, such as phenolic which preferably isblack.

As is shown in FIG. 2, the baffle unit 36 is desirably formed from twosemi-circular sections 36a and 36b, the abutting longitudinal edges 37of which have complementary projections 38 and recesses 39 to retain thesections together in proper alignment.

Means are provided securely yet releasably to mount the baffle unit 36in the casing 11. To this end, each of the sections 36a, 36b on itsouter surface adjacent its lower end 41 has an inwardly inclined recess42 defining an annular locking shoulder 43.

Coacting with the shoulder 43 are screws 44, each of which extendsthrough an opening in the end of the inwardly inclined leg 45 of abracket 46, the inwardly extending horizontal leg 47 of which is securedas by welding to the flange 28 as is shown in FIG. 1.

The inner surface of the bafile unit is molded with a multiplicity ofannular ribs 51 each having a flat top surface 52, a relatively sharpinner end 53 and a downwardly inclined bottom surface 54 which extendsto the root end 55 of the top surface of the rib therebelow.

In assembling the fixture with the gasket 32 mounted on flange 28between cylindrical portion 26 and bracket 46, the baffle unit 36 mayfirst be securely mounted on the flange 28 by positioning the lower end41 of the baffle unit 36 on the flange 28 and then tightening the screws44.

The cylindrical portion 26 is then positioned over the lower end of thecasing 11 and the screws 33 tightened, the resilience of the gasket 32eliminating the need for close tolerances in the formation of the holesthrough which screws 33 extend. Thereupon, the unit thus assembled ispositioned in the recess in the ceiling and retained in place inconventional manner with the flange 29 resting on the periphery of theopening 27 in the ceiling.

When the lamp 17, which illustratively is of the projection type, isilluminated, a substantially cylindrical beam of light will be projecteddownwardly to strike the object that it is desired to illuminate.

It is to be noted that the rays of light emanating from the lamp 17,other than the vertical components thereof, would strike the innersurface of the bafile. In the absence of the ribs 51, even if such innersurface was black, if it presented an uninterrupted surface, somereflections would still occur. This would cause an undesirablebrightness within the confines of the baflie which would provide abright region on the ceiling that contrasted strongly with thesurrounding area and hence would focus the attention of the viewer onthe source of light itself rather than on the object being illuminated.

The ribs 51 serve substantially to eliminate reflections due tonon-vertical components of light from the lamp 17 and hence brightnesswithin the confines of the baffle is substantially eliminated.

Thus, referring to FIG. 3, as the rays of light strike the inner surfaceof the bafile, the rays will take the path illustrated at L so that thevisible portion of the inclined bottom surfaces 54 of the ribs will bein a shadow. Thus, reflections due to non-vertical components willsubstantially be prevented and as the edges 53 of the ribs 51 arerelatively sharp, the reflections therefrom will be at a minimum.

Based upon the angle a between a line X extending through the filament61 of lamp 17 in a plane at right angles to the axis of the bafile unit36 and a line Y extending from such filament to the lower end 41 of thebafile unit, the angle of cut off of the unit may be determined.

This angle is such that a person would have to be relatively close to aline extending vertically from the filament before he could directly seethe lamp 17. Consequently, by keeping the angle of cut oif say greaterthan 45 degrees, a person in the room at a relatively small distancefrom a vertical line from the filament 61, even if he looks directly atthe ceiling will not be able to see the lamp itself which would beblinding to his eyes.

As many changes could be made in the above equipment, and manyapparently widely different embodi- 3 ments of this invention could bemade Without departing from the scope of the claim, it is intended thatall matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

A lighting fixture comprising a substantially cylindrical casing havinga mouth at one end and a wall at the other, an annular flange releasablysecured to the mouth of the casing and extending inwardly thereof, abaflle member comprising a sleeve of opaque plastic material having amultiplicity of longitudinally spaced annular ribs on the inner surfacethereof and molded integrally therewith, each of said ribs beingsubstantially triangular in cross section having a flat top wall and abottom Wall inclined downwardly from the inner edge of the top wall tothe root end of the top wall of the rib immediately below, the inneredge of each of said ribs being relatively sharp, the periphery of saidbaflle member at its lower end resting on the inner periphery of saidflange, a portion of the outer surface of said sleeve adjacent the endthereof resting on said flange tapering inwardly to define an annularlocking shoulder, means carried by said flange reacting against saidshoulder releasably to retain the baflie member in said flange, and asocket mounted on said casing wall adapted to support a lamp.

References Cited in the file of this patent UNITED STATES PATENTS1,839,022 Froget Dec. 29, 1931 1,879,442 ONeil Sept. 27, 1932 1,903,417Grant Apr. 11, 1933 2,539,927 Ramminger Ian. 30, 1951 2,587,423 YoungFeb. 26, 1952 2,795,690 Cooper June 11, 1957 2,796,517 Herzfelder m.June 18, 1957

